Thermoresponsive device



' air temperature variations.

Patented Oct. 14, 1941 UNITED STATES' PATENT. OFFICE 2,259,061 'rneaMom-:sronslvn DEVICE f Pierre L. Gamer, Brooklyn, N. Y. Application July so, 19:7, seran No. l156,421;

z claims. (c1. 2cv-1c).-

This invention relates to a simple method, and eiiicient means, to cause a thermo-responsiveelement to conform instantly and accuratelyv to Theinvention will be describedwith reference to the accompanying drawing. in which Figure l is a view in front elevation of'an embodiment of the invention showing certain elements in transverse section and other elev ments partly in dotted lines.

Figure 2 is a vsectional elevation on the line 2 2, Figure 1.

Figure 3 is a diagrammatic view, partly-in section, showing the application ofthe device to an air conditioner for rooms.

Figure 4 is an enlarged vertical section taken longitudinally through the inlet end of the air inlet pipe for the air conditioner showing a Venturi connection between the temperature-responsive device and said pipe.

The sluggishness of thermo-responsive elements'in reacting to changes in temperature of fluids such as air, as is well known to those skilled in the art of temperature control, is dueto a slow process of heat transfer between the' thermo-responsive element and the air in which it ,is disposed, this.conditioncgettingimore ob# for example, by heat-induced rising air currents, which are entirely too feebleand not properly directed to removethis "surface iilm.

.Inrthe drawing, I have shown a thermo-responsive-element I inthe form `of a' relatively heavy spiral spring. 'I'he temperature-responsive element may be of any form adapted to transmit a moving force to a registering or control element suchas a switch arm, for example,

The element may be a bimetal spring and due to the'invention, the bimetal spring or other form ofV temperature-responsive element may be made relativelyv heavy to transmit adequate power, to

Vclose or open a switch for example, and, at the same time, be highly` responsive to air temperature variations. The outer end of the spiral spring I is held in fixed position to a casing wall in the form of a tube 2 which, in the present embodiment, completely encircles the spring. The innerV end of the spring is fixed to a sleeve 3 through which passesa headed stud 4 threaded at one end.V Tightly tted on stud 4 is' the lower the surrounding air or vice versa. Most metals being generally good heat conductors, it then becomes obvious that the removal of this lm will make a; bimetal thermo-responsive element highly sensitive to air temperature variations even though the` mass of said thermo-element may still be rather large, and the temperature dinerence between the element and the air may be very small.

By my invention this film is positively removed by the rapid motionr of air forced over and close to the radiating surface of thev thermo-responsive element, with the result of instant response to air temperature variations. This cannot be acend of a switch arm 5, a nut 6 threaded on stud 4 serving to clamp thefend of the switch arm against washers 1.

To the upper end of arm 5 is secured an insulating block 8 which, in turn, carries. a conventional type of magnet switch which comprises the spring-contact-carrying-element 9, the contact being indicated at 9a.', and a rigid back plate Ill. A t the rear of the back plate is a phosphor bronze cushioning arm II to reduce sparking, which is well known in this art.

` A supporting panel I2 is apertured to receive 7 tube 2 -and the tube or a member connected thereto may be formed with a' depending area, or, as shown in the drawing, a ange 2z which may be apertured to receive a retaining v stud I3 threaded in panel I2. The aperture for the stud in ange 2a: is elongated as shown more particularly in Figure 1 at Il.

Carried by the tube 2 adjacent one face of panel lzis an adjustingarm 2m. The arm will be held against the panel by means of the stud I3. Additional means comprises screw I5 which passes through an arcuate apertureat a in an intermediate wing areaV of arm 211:, the screw being utilized to hold in position the contact assembly which coacts with contact Sz. The said contact assembly comprises a bracket I6 through which screw, I5 passes, the bracket carrying the adjustable contact pin I1 (Figure 1) and also a conventional magnet I8.-

Contact-carrying arm l. has connected thereto I mplished by ordinary convection as created. a plgtail wire I9, one end of the wire engaging 2 a screw 20 passing through the panel and receiving wire 20x. When contact 9:: engages contact pin I1 an electrical circuit is closed through wire 202:, the switch elements including pin I1, bracket I8, screw I5 and wire 201:1: secured to the latter screw. Wires 20.1, mm will lead to the element to be energized and the source of power in a series circuit giving 4direct line voltage operation.

At the front of the panel a cover 2| may be provided and the cover may be formed with an internally projected tube 2Ix to shield all of the elements carried by the panel with the exception of the thermo-responsive spring I. Rearwardly of the panel, tube 2 will communicate with a conduit such as 22 which will lead to means for forcibly drawing air through tube 2 from the room or chamber in which the thermo-responsive device is located.

In the present embodiment the means for forcibly causing a current of air to pass over the surfaces of the thermo-responsive element comprises the intake pipe 23 or an air conditioner 24. To aid in the suctlonal force created through pipe 23 by fan or other suction means ,of the air conditioner, a venturi 24 may be placed in pipe 23 and pipe 22 led into the venturi as shown more particularly in Figure 4. The outflow duct leading from the air conditioner is indicated atv 25 and it passes through a wall 26 near the top thereof, a conventional form of screen being indicated at 21. Pipe 23 being the return duct of the air conditioner, likewise passes through wall 26 and a conventional form of screen 28 is shown applied thereto. A fresh air duct for the air conditioner is shown at 23 leading to the outside air.

In the operation of the device, the operating diiferential is adjusted by rotating adjustable threaded pin I1 by means of thumb head |13: (Figure 1), thereby changing its position in the field of the magnet.

'I'he temperature adjustment for the room is effected by moving arm 21cm to the left or the right, and the arm may carry or be marked with a pointer as indicated. at p, the degree of adjustment being indicated on the plate by the marking at d.

As air is withdrawn from the room or chamber in which the device is located, through the action of the air conditioner, the suction through pipe 22 will force air through tube 2 and the air will be drawn uniformly over the entire surface of the To aid in this uniform action of tion will be unimpeded and hence the thermoresponsive element will conform itself to the temperature of theair with practically no time lag.

It will be understood that the means :or causing a forced draft of air across the surface of the thermo-responsive element may be widely varied from that illustrated in the drawing. This method of film removing must not be confused with y spond with the precise manner as realized in my invention.

It will also be noted that the rotary motion furnished by the thermo-responsive spiral spring may actuate or throw into action any form of electricalswitch such as a mercury capsule, etc., the drawing being illustrative of one embodiment only. A spiral was chosen as being the most convenient shape to obtain motion and still retain a fairly equal space between convolutions so the fairly constant stream or air of high velocity be continuously maintained in intimate contact with the surface of the element. Any other form of element so shaped that a thin stream of air at high velocity can be made to remove the surface film can be substituted.

Having described my invention, what I claim and desire to secure by Letters Patent is as follows:

1. A surface film-free thermo-responsive element reacting to variations in temperature of air at atmospheric pressure, comprising a spiral bimetallic spring having closely wound convolutions, a device operatively connected to and adapted to be thrown into action by said element, a tubular wall surrounding the spring and spaced therefrom approximately the same distance as the spacing between the convolutions, and means for causing a continuous air stream of high velocity to pass in direct and intimate contact with all the surfaces of the spring transversely thereof.

2. A thermo-responsive element reacting to temperature variations of air at atmospheric pressure comprising a bi-metalllc spiral spring having closely wound convolutions, a device operatively connected to and adapted to be thrown into action by said element, and means for causing a stream of said air at high velocity to continuously brush the surfaces of the spring from edge to edge of its tape convolutions, thereby preventing said air from forming an insulating film upon the surfaces of said spring.

- PIERRE'L. CAFFIER. 

